<template>
  <div>
    <span>全选:</span>
    <input type="checkbox" v-model="isAll"/>
    <button @click.prevent="btn">反选</button>
    <ul>
      <li v-for="(item,index) in arr" :key="index">
        <input type="checkbox" v-model="item.c"/>
        <span>{{item.name}}</span>
      </li>
    </ul>
  </div>
</template>

<script>
export default {
  data() {
    return {
      arr: [
        {
          name: "猪八戒",
          c: false,
        },
        {
          name: "孙悟空",
          c: false,
        },
        {
          name: "唐僧",
          c: false,
        },
        {
          name: "白龙马",
          c: false,
        },
      ],
    };
  },
  computed:{
    isAll:{
      set(val){
        return this.arr.forEach(obj=>obj.c=val)
      },
      get(){
        return this.arr.every(obj=>obj.c)
      }
    }
  },
  methods:{
    btn(){
      this.arr.forEach(obj=>obj.c=!obj.c)
    }
  }

};
</script>